With this well-tuned kit, you can breathe more life and sovereignty into your original, rather sluggish motorized Vespa and thus participate more actively in traffic. The Polini cylinder in classic cast iron technology is solid and robust. The design of its timing is more torque-oriented, so that you have a lot of power from the bottom, which takes the fear out of hills and rides for two. However, this also means that it requires a longer gear ratio, for which the engine must be opened. As a rule, however, this is a sensible undertaking anyway, as many engines have been rather neglected and sometimes have over 20000 km on the clock without ever having been overhauled. Once the engine is open, the performance-enhancing racing crankshaft from BGM is used directly across the entire rev range. The larger Dell'Orto carburetor with 20 mm not only provides more power, but also better internal cooling, which helps with thermal stability. Simply start with the largest HP and slowly jet down until the scooter runs perfectly and the spark plug pattern is correct. The ignition should be flashed and checked at 17°f.t.
With a clean installation and good adjustment, 5-6kw are available at the rear wheel at a moderate 6500 rpm. This power is easily enough to drive over 80 km/h. The engine power and characteristics can be significantly altered with a different exhaust. Our insider tip is the ETS banana with manifold for 50cc engines. It also fits the PK models without modifications (spare wheel is omitted), is very inconspicuous and still has the typical Vespa sound. A sportier alternative is the Polinibanane. This extends the rev range significantly further upwards without weakening in the lower rev range. The only drawback is its significantly stronger sound compared to the ETS banana
. Visually and acoustically, the entire conversion is extremely discreet and barely noticeable
. The basic engine should of course be in a healthy condition for this and not have too high a mileage. Otherwise, we recommend overhauling the fuselage engine before tuning. Parts, shaft seals, bearings, engine gaskets etc. can be found in our online store.
Further tuning stages are possible, with resonance exhaust systems and an enlargement of the rotary valve inlet area in the engine housing. A new tuning of the engine is then of course obligatory.
Scope of delivery:
DE | €
